The present invention relates to an indoor fish tank, comprising walls and floors which define a tank container having a fish holding section, a sedimentation section connected via at least one opening to the fish holding section in such a way that water from a region close to the groundflows from the fish holding section into the sedimentation section, and a bioreactor section which is connected via at least one opening to the fish holding section in such a way that water from a region close to the upper surface flows out of the bioreactor section into the fish holding section.
Overfishing and environmental influences have led to a stagnation of fishery yields worldwide, and to a decline in yields for some species of fish. One promising approach for preserving natural fish stocks is to breed fish in aquacultures. A distinction is made here inbetween extensive and intensive aquacultures, wherein intensive aquacultures are able to produce higher yields than extensive aquacultures due to artificial feeding.
Fish ponds, launder systems and net pen aquacultures are aquaculture methods that are currently used to significant commercial extent. However, each of these forms of aquaculture exhibit specific problems caused by factors relating to approval regulations, on the one hand, and relating, on the other hand, to the need for a continuous supply of fresh water (in the case of launder systems), and to the continuous removal of fish feces and food remnants into the natural surroundings (in the case of net pen aquaculture).
For many years, work has therefore been carried out to develop aquacultures that are designed as recirculation systems. These recirculation systems are also referred to as indoor fish farms, and are distinguished by fish being bred within a closed water circulation system. It should be understood in this regard that fish tanks of such recirculation systems are preferably erected inside buildings, although this indoor fish breeding technique in such recirculation systems could also be used outdoors.
A fish tank for fish breeding, suitable for intensive fish aquaculture in the form of a recirculation system, is known from German patent DE 195 21 037, the entire disclosure of which is incorporated herein by reference. From a technical perspective, the bioreactor section and the sedimentation section are considered important elements of such a fish tank. In the sedimentation section, solids are sedimented and removed from circulation, which necessitates feeding a small amount of fresh water as compensation into the (semi-)closed circuit. In the reactor section, oxygen is supplied by means of a finely distributed aeration system to the breeding water, and the organic substances are decomposed intensively by micro-organisms therein.
Fish tanks of this kind are basically well-suited for a recirculation aquaculture. However, there is a need for improvements to be made to enable more efficient management of these fish tanks in larger fish farms, and in particular to enable maintenance work to be carried out more easily on the fish tank.
There is also a need for fish tanks that can be installed in a more cost-efficient manner than prior art fish tanks.
Finally, there is a need for indoor fish tanks which make it easier to harvest the fish.